What is the lifetime of a solar power system?

The life span between a cheap and a quality solar system differs. For example high quality inverters on average can last longer than a decade, while some very cheap inverters may have high failure rates after only a few years. Solar panels do not have any moving parts and if they are of a good quality can last a long time. LG solar panels, for example, are expected to reliably generate electricity for 25 years. 

In general you should look at the following as the minimum life of a system:

1. 10 year manufacturing warranty on Solar Panels
2. 25 year limited warranty on power production of the solar modules
3. Minimum of 5 years manufacturer’s warranty on the inverter. Some solar inverter manufacturers offer a 10 year warranty(parts and labour) or the option to extend the inverter warranty for 5 years to 10 years for a small extra fee.
4. Also confirm that the installer gives you a long workmanship warranty on their installation work.